Luminaire



Jan. 31, 1961 D. E. HUSBY ETA; 2,970,222

LUMINAIRE Filed May 19, 1958 2 Sheets-Sheet l WITNESSES INVENTORS DonaldE. Husb 8 w BThomas A.Jent\er flfy m7 ATTORNEY Jan. 31, 1961 D. E. HUSBYETAL LUMINAIRE 2 Sheets-Sheet 2 Filed May 19, 1958 United LUMINAIREFiled May 19, 1958, Ser. No. 736,042

'6 Claims. (Cl. 250-239) This invention relates to luminaires, andparticularly to streetlighting luminaires, having control elements, suchas photoelectric lighting control units, transformers and the like, andmore particularly to the luminaire mounting arrangement, and manner ofincorporating such elements in a luminaire mounting.

The use of photoelectric control units for turning lights, for example,streetlights, off and on depending upon the intensity of the surroundinggeneral illumination, is well known. It is common practice to providephotoelectric control units for this purpose and these units are usuallymounted to the support pole or to a separate bracket attached to thesupport pole, or directly to the luminaire housing. Likewise,transformers have for most part been separately mounted.

The present invention relates to a luminaire of such construction thatcontrol components may be mounted directly to or in an extension of thehousing of a luminaire. If it is so desired, the photoelectric controlunit may have a mounting integral with the luminaire housing. The use ofspecial mounting brackets for these controls are dispensed with, and acompact and attractive installation is achieved.

This invention has for its general object the provision of a luminairehaving a photoelectric control unit which is mounted on the luminairehousing in a novel manner.

Another object of this invention is to provide a photoelectric controlunit which is constructed with a novel support to be mounted to thehousing of a standard luminaire. Still a further object of thisinvention is to provide a luminaire having novel integral mounting meansfor a photoelectric control unit located on a portion of its housing.

Still another object of this invention is to provide a luminaire havinga novel housing construction with a transformer mounted within thehousing in a novel manner.

A further object of this invention is to provide a luminaire having ahousing with a transformer mounted there in by novel means associatedwith the transformer laminations. 7

A more particular object of this invention is to provide a luminairehaving a novel housing supporting a photoelectric control unit, whichhousing has an associated electrical component mounted closely thereinin a new and novel manner so as to occupy the least amount of space buthaving the greatest utility.

These and other objects of this invention will become more apparent uponconsideration of the following detailed description of a preferredembodiment thereof, when taken in connection with the attached drawings,in which:

Figure 1 is aside elevation view of the luminaire and associatedphotoelectric control unit constructed in accordance with thisinvention, with certain of the parts shown in section;

Fig. 2 is a side elevation view of a modified form of a '2 atent OPatented Jan. 31, 1961 luminaire and associated integrally mountedphotoelectric control unit and transformer constructed in accordancewith this invention, with certain of the parts shown in section; and

Fig. 3 is an end view of the luminaire housing shown in Fig. 2 with therefractor globe and the upper transparent portion of the photoelectriccontrol unit removed.

While the invention is herein specifically disclosed as embodied in astreetlighting-type of luminaire, it should be understood that theinvention in its various aspects may find application in other types ofluminaires, and consequently, the following specific disclosure is notintended as limiting with respect to any of the features of thisinvention.

Referring to the drawings in detail, Fig. 1 illustrates an example ofthe streetlighting luminaire having a housing of the type shown indetail and more completely de scribed and claimed in Patent 2,849,574 ofRobert T. Burns and Dana W. Rowten, entitled Luminaire, applicationSerial No. 518,844, filed June 29, 1955, and assigned to the sameassignee as this invention. The housing portion 2 has an integral sideextension or cast slipfitter portion 10 extending outwardly from themain portion of the housing portion 2. The housing slipfitter portion 10has an integral cast mounting sleeve portion 48 at its outermost portionwith openings at each of its ends. The housing slipfitter portion 10 hasa generally inverted U-shape substantially providing an opening in thebottom thereof. The streetlighting luminaire shown in Fig. 1 has ahousing portion 2 with an inverted cup-shaped reflector 11 locatedtherein, and a refractor globe 14 mounted over the open side of thereflector 11 and housing portion 2.

In the example shown, the housing slipfitter portion 10 supports aphotoelectric control unit 16 on the upper part thereof. Thephotoelectric control unit 16 is supported on the housing slipfitterportion 10 by means of tubular adapter fitting 21 having exteriorthreads to be internally threaded at one end within a threaded openingin a boss 19 formed integral with the top wall of the slipfitter portion10. The photoelectric control unit 16 has a base housing 23 generallycup-shaped in form with a peripheral shoulder 27 about its outer, uppersurface, and an integral hexagonal collar 25 at the bottom thereof witha central opening therethrough provided with internal threads toaccommodate the other end of the tubular adapter fitting 21. Thehexagonal collar 25 may be used to rotate the base housing 23 tothreadedly engage the adapter fitting 21. Once the base housing 23 andthe adapter fitting 21 are engaged, the outer portion of the hexagonalcollar 25 may also be used to threadedly engage the adapter fitting 21to the internally threaded boss 19. Lead wires 69 extend through theadapter fitting 21 and are connected to a plug-in receptacle assembly 40located in the base housing 23. The photoelectric control unit 16 may bethreadedly engaged in the boss 19 prior to connecting any of the leadwires 69 to the electrical components located within the housingslipfitter portion 10, which will be described hereinbelow.

The plug-in receptacle assembly 40 has a peripheral flange 41 about itsbase, and is designed to accept a plugin receptacle cartridge (notshown). For purposes of obtaining the best light to actuate thephotoelectric cartridge (not shown) the plug-in receptacle assembly 40may be rotated within the base housing 23 so as to orientate thephotoelectric cartridge in a generally northerly direction. A machinescrew 34 inserted in tapped holes 42, located in the inner, bottomsurface of the base housing 23, and having a lock washer 36 and a washer38 thereon, is tightened with the washer 38 engaging the flange 41 ofthe plug-in receptacle 40, once the northerly direction has beendetermined, to thereby secure the plug-in receptacle assembly 40 on thereceptacle assembly seat 22 which is recessed centrally in the upper,inner surface of the base housing 23. A die-cast lock ring 26,preferably made of cast aluminum or the like, peripherally engages theshoulder '27 of the base housing 23 and is attached thereto by means ofla'liquid body .solder, an epoxy resin or by welding 24. A control unitcover 32, made of any suitable transparent material such as glass,.isreleasably secured to the die-cast lock .ring 26 by a cover assembly 28such, for example, as that describedin patent application Serial No.531,657, now abandoned, entitled Meter Cover Assembly, by Frederick W.Witte, filed August 31, 1955, and assigned to the same assignee as thisinvention. A gasket 30, made of a suitable compressible weatherproofmaterial, such as rubber, is mounted in a recess provided in the uppersurface of a peripheral flange 31 formed integral with the die-cast lockring '26, and is engaged by the control unit cover 32 .to provide awaterproof seal therebetween.

Aspreviously described, the housing slipfitter portion has aphotoelectric control unit 16 mounted on'its upper wall. The housingslipfitter portion 10 has integrally formed with its upper, innersurface spaced terminal block bosses 65 adjacent opposite sides whichextend downwardly. A terminal block 60, directly mounted to an elongatedflatplate 64 by a nut and bolt assembly 62, is mounted to the terminalblock bosses 65 by bolt and lock washer assemblies 67 extendingthroughholes in the elongated flat plate 64 and into threaded openings providedin the bosses 6.5. The terminal block 60 extends substantially-entirelyacross the housing slipfitter portion 10. Laterally spaced reinforcingribs 71 (only one of which is shown), extend longitudinally of theinner, upper wall of housing slipfitter portion 10.

The mounting sleeveportion 48 which is integrally formed with thehousingslipfitter portion 10, has a yoke 51 mounted adjacent its outerend. The yoke 51 is of a'generally U-shape and is movable in a slot 49provided in thelower wall of themounting sleeve portion 48 with the endsthereof extending through openings in the tQP wall of the sleeve portion48 and having yoke nuts 53 threadedly mounted thereon to be drawn upinto clamping engagement with a-pipe support (not shown), to firmlysupport the housing portion 2. An upper set screw 50, and a lower setscrew 52, located in the mounting sleeve portion 48 are provided toadjustably align the housing portion 2 on the. pipe support (not shown)In the mounting sleeve portion 48,.inwardly of the yoke 51. is aringshaped pipe stop 55 formedintegrally with the housing slipfitterportion 10, to prevent a pipe support from extending inwardly of thehousing slipfitter portion 10 .beyond the pipe stop 55. Thepipe stop 55has a circular gasket 57 made of any suitable waterproof, gasketingmaterial, such asrubber, to whicha ,pipe support may be abutted. Thecircular gasket ring 57, when the pipe support is in position, willprevent the entranceof any insects or dust present about the pipesupport from entering the internal areas of the housing slipfitterportion 10. Conductors (not shown) may easily be inserted from the pipesupport into the slipfitter housing portion 10 through the aperture ofthe circular gasket 57 and the pipe stop 55 to be connected to theterminal block 60.

A lamp socket 73, as shown in Fig.1, is mounted within the housingslipfitter portion 10 to extend inwardly of the reflector 1 1 to therebymount an electric lightsource therein (not shown). The lamp socket 73 issupported in position by a lamp socket strap 77 which extends beneaththe socket 73 and has its outer ends attached to laterally spaced lampsocket bosses 7-5 integrally formed with the housing slipfitter portion10 and extending downwardly from the upper, inner side portion of thehousing slipfitter portion .10. .Screws 79 pass throughthe outer endsofthe lamp socket strap 77 andengage tapped holes in the lamp socketbosses 75.

The refractor globe 14 is illustrated in Fig. l as being latched inposition where its "upper rim 116 is in engagement with a sealing gasket78, made of any suitable material such as felt, which in turn engagesthe lower flange 118 of the housing 2. The refractor globe 14 is adaptedto be releasably supported in closed relation with the bottom opening ofthe housing 2 by a pivot support at one end adjacent the housingmounting sleeve 10. The pivot support comprises a pair of supportingarms .83 provided integral with the refractor globe ring 82and joined attheir outer ends .by a pivot pin 85. A hook shaped support 87, securedto an integral transverse support extending across the underside of themounting sleeve 10 adjacent the refractor globe 14 by mounting screws93, pivotally mounts the pivot pin 85, thereby hingedly mounting therefractor globe 14 to the housing for movement to the open or closedposition relative to the bottom openings of the reflector Y11 andhousing portion 2. There is also provided a leaf spring'8 1, attached tothe refractor globe ring 82 intermediate the pivot pin supporting arms83 so as to extend downward a distance and then 'arcuately upwardly andoutwardly, so as to engage an integrally formed lip 63 located on thebottom portion of the housing slipfitter 10. The leaf spring 81 isbiased by the lip 63 in the closed position as shown in Fig. 1, therebyforcing the refractor globe 14 and the refractor globe ring 82 upwardlyagainst the gasket'78 to form a dust proof and bug proof joint. It is tobe noted, that when the refractor 14 is-in its closed position, therefractor globe ring 82 is supported by the leaf spring 81, and thepivot pin 85 is restrained from transverse movement by the hook shapedsupport 87. To open the luminaire, the refractor globe 14 and therefractor globe ring 82 are rotated downwardly about the pivot pin '85so that the leaf spring 81 disengages lip 63 allowing the pivot pin 85to drop to the bottom of the hook shaped support 87. The refractor bowl14 may be further rotated until the flat surfaces 150 on pivot pinsupporting arms'83 are at a position to clear the lip'63 whereupon therefractor globe 14 and the refractor globe ring 82 may 'be lifted tomove the pivot pin 85 upwardly and out of the slots in the hook shapedsupport 87.

In the particular embodiment shown in Fig. l, the housing slipfitterportion10 has its bottom opening located intermediate the hook shapedsupport 87 and the mounting sleeve portion 48 and it is covered by aremovable closure door 89 supported in its closed position byoutwardlybiasedleaf springs 91 secured to opposite ends of the door 89 to engagethe opposite ends of the opening in the bottom port-ion of housingslipfitter portion 10.

In another embodiment of applicants invention, as shown in Figs. 2 and3, certain of theparts are identical with those described above inconnection with the embodiment of the invention shown in Fig. 1,andconsequently the same referencenumerals :are employed to designatesuch parts,-and .a detailed description thereof will not be repeated.'In this embodiment of the invention, the housing slipfitter portion 13has an upwardly extending supporting extension 18 formed integrally onits upper wall. The housing slipfitter portion 13 is generally ofinverted U-shape in form with support mounting means in an integralmounting sleeve portion 48 located at its outer end, anda bottom openingextending its entire length. The upwardly extending support extension.18 is circular in cross section and has an inwardly projectingperipheral flange portion 20 which extends downwardly from the topperiphery of the supportextension 18. The inwardly projecting flange 20extends inwardly to a radius substantially half of the radius of thecircular housing extension 18. An integral horizontal ring-shapedreceptacle assembly seat 22 is integrally formed with the inner end ofthe projecting-flange portion 20. The circular-receptacle assembly.seat-22 ,forms a peripheral flange upon which the plug-in receptacleassembly 40 with its associated electrical conductors (not shown)extending through the opening of the receptacle assembly seat 22. Theplug-in receptacle assembly 40 may be positioned to face in a generallynortherly direction, and then machine screw 34, cooperating with lockwasher 36 and washer 38, may be tightened in a tapped hole 42 tosecurely hold the receptacle assembly flange 41 of the plug-inreceptacle assembly 40 in position. A photoelectric control cartridge(not shown) is inserted in the plug-in receptacle assembly 4|) with itslight sensitive component part located within the control unit cover 32.The lead wires (not shown) extending downwardly from the receptacleassemby 40 may be readily connected to the transformer assembly 70,terminal block 60 and lamp holder 74. As previously described, relativeto the embodiment shown in Fig. 1, a die-cast lock ring 26 is mounted tothe shoulder 27 of the housing extension 18 and secured thereto by meansof a body solder, epoxy resin or welding 24.

In the particular embodiment of applicants invention as shown in Fig. 2,the transformer assembly 7 0 comprising a laminated core 59, and a coil61, is located in the housing slipfitter portion 13 directly beneath thephotoelectric control unit 16. Bosses 46 are integrally formed atopposite side walls 104 of the housing slipfitter portion 13 and eachhas a tapped hole 102 to accommodate elongated machine screws 68.Elongated laterally extending integrally formed supports 44 extendvertically downward from the upper, inner wall of the housing slipfitterportion 13 and at right angles to the side walls 104. The transformerassembly 70, which is mounted by the machine screws 68, has dovetailedslots 106 formed in opposite sides of the laminations of the core 59,which may be used for orientation of the transformer core laminations 59during assembly, and these slots 106 are used to guide and accommodatethe machine screws 68. A spacer 72 is located under the head of eachmachine screw 68, and engages a substantial portion of the adjacenttransformer core 59 so as to distribute the load on the transformercore. 59 when the machine screw 68 is threadedly engaged with the boss46 and tightened to secure the transformer core 59 against the supports44. At the side of the transformer assembly 70 adjacent the housingsleeve portion 48, a nut and bolt assembly 66, passing from top tobottom through the laminations of the transformer core 59, mounts aterminal block 60. The terminal block 66 is mounted to an elongated fiatplate 64 by means of a nut and bolt assembly 62, and the plate 64 ismounted beneath the head of the bolt used in the nut and bolt assembly66, to thereby securely hold the plate 64 and the terminal block 60 inposition.

To further support the housing slipfitter portion 13, as shown in Fig.2, a cross brace 80, shown in cross section in Fig. 2, is integrallyformed with the lower portion of the housing slipfitter portion 13between the side walls 104 at the inner end thereof. Immediately abovethe cross brace 80 in the housing slipfitter portion 13, another crossbrace 108 is integrally formed with the housing slipfitter portion 13between the side walls 104. An inverted cup-shaped reflector 12 ismounted at one end to the cross braces 80 and 108 by nut and bolt assemblies 94. A lamp socket 74, having connector terminals 76 extendinginwardly of the housing slipfitter portion 13 so as to be locatedadjacent to the transformer assembly 70, is securely fastened to thereflector 12 by nut and bolt assemblies (not shown) located adjacent tothe aperture 110 in the reflector 12 through which the lamp socket 74extends.

A refractor globe 14, as shown in Fig. 2, is mounted in a refractorglobe ring 82. A gasket 78, made of any suitable gasketing material,such as rubber or a fibrous material separates the upper rim 116 of therefractor globe 14 from the bottom outwardly extending flange 114 of thereflector 12. The gasket 78 provides a dust-proof and bug-proof seal forthe interior of the luminaire. A

wide, flat hinge spring 92, attached at its upper end to the cross braceby nut and bolt assemblies 94, extends outwardly and downwardly toprovide a hook-shaped hinge at its lower end. A refractor globe ringhinge 112 in the general form of a U-shaped rod is integrally mounted toextend outwardly of the refractor globe ring 82 and has its leg portionsarcuately bent downward so as not to interfere with the reflectoroutwardly extending flange 114. The bight portion of the refractor globering hinge 112 seats itself within the hook-shaped portion of hingespring 92 to rotatably mount the refractor globe ring 82.

Opposed bosses 88, integrally formed with the inner side walls 104 ofthe slipfitter housing portion 13 extend vertically downardly from theupper to the lower portions of the side walls 104, and have tapped holesat their lower ends to accommodate bolts 90. As previously stated, thebottom portion of the housing slipfitter portion 13 is open. Anelongated flat plate bottom cover 86, having an upwardly bent verticalportion at its outer end, may be mounted to the bosses 88 by the bolts90. The bottom cover 86 substantially encloses the bottom opening of thehousing slipfitter portion 13. The vertical portion 1% extends upwardlyinto the mounting sleeve portion 48 to substantially fit about a pipesupport that will be described hereinbelow. The bottom cover 86 and itsupwardly extending vertical portion 100 will thus provide protection forthe electrical components mounted in the slipfitter portion 13.

The mounting sleeve portion 48 is integrally formed with the outerportion of the housing slipfitter portion 13. Similar in shape to theU-shape of the housing slipfitter portion 13, the mounting sleeveportion 48 is tapered to its outermost extremity. Midway the length andat the lower portion of the mounting sleeve portion 48, there is locatedan integral arcuately downwardly bent cross bracket 54, as shown in Fig.3. Securing bolts 50 and 52 are located in the upper outer end of themounting sleeve portion 48, and the cross bracket 54, respectively. Thebolts 56 and 52 are used to secure the slipfitter housing portion 13 toa pipe support 96 or 98, shown in dotted lines. The cross bracket 54 hasa partially circular shape so that it may accommodate the large pipesupport 98 when it is inserted into the mounting sleeve 48 and abutsagainst an integral pipe stop 84, extending downwardly from the upperportion of the inverted U-shaped mounting sleeve portion 48 at its innerend. If the smaller pipe support 96 is used to mount the housingslipfitter portion 13, a flat plate adapter 56, having a semicircularshaped upper edge 47 to accommodate the outer diameter of the smallerpipe support 96, is mounted to the cross bracket 54 by the adapterscrews 58 which threadedly engage tapped holes (not shown) horizontallylocated in the cross bracket 54 to securely hold the adapter 56 inplace. The adapter 56 and the pipe stop 84 will adequately position thesmaller pipe support 96, whereupon upper set screw 50 and lower setscrew 52 may be tightened to securely hold the pipe support 96 in placeafter alignment of the housing slipfitter portion 13 has been made. Boththe pipe supports 96 and =98 are hollow to accommodate electricalconductors (not shown) which pass therethrough and into the luminairehousing. It is to be noted that the terminal block 60 is located closelyadjacent to the end of the pipe support 96 or 98 so that electricalconnections may easily be made thereto when the cover 86 is removed,

While certain preferred embodiments of the invention have beenillustrated and described in detail, it is to be understood that changesmay be made therein and the invention embodied in other structures. Itis not, therefore, the intention to limit applicants invention to thespecific construction illustrated, but to cover the invention broadly inwhatever form its principles may be utilized. Accordingly, it is desiredthat the invention be given a broad scope and that it be limited only asrequired bythe .prior art.

We claim as our invention:

1. A luminaire comprising, an inverted cup-shaped reflector, an aperturelocated in said reflector, a lamp supporting means mounted adjacent saidapertures for supporting a lampvin-said reflector, an'elongated housinglocated adjacent to and extending outwardly from the apertured portionof ,said reflector, support means on said housing opposite saidreflector, an internally threaded aperture located on a portion of saidelongated housing intermediate said reflector and said supporting means,an at least partially transparent enclosure having a base suitable formounting electrical control components, electrical control componentslocated in said enclosure being light sensitive, a threaded pipe supportlocated in the base of said enclosure suitable for threaded ly engagingthe aperture, said pipe support being an electrical conduit between theinterior of said housing and said enclosure, said electrical componentslocated in said enclosure automatically energizing said luminaire.

2. A luminaire comprising, an inverted cup-shaped reflector, an aperturelocated in said reflector, a lamp supporting means mounted adjacent saidaperture for supporting a lamp in said reflector, an elongated U-shapedhousing located adjacent to and extending outwardly from the aperturedportion of said reflector, support means in said housing opposite saidreflector, an at least partially transparent enclosure integrallymounted and located on a portion of said elongated housing intermediatesaid reflector and said supporting means, a transformer having a core,securing means engaging integral bosses extending inwardly on the innerside of said U- shaped housing for securing said transformer in place,dove-tailed slots located in each side of said transformer core forreceiving said securing means, supports extending inwardly of saidhousing to position and further support said transformer, so that saidtransformer is closely associated with all electrical components toprovide easier wiring for said luminaire.

3. A luminaire comprising, an inverted cup-shaped reflector, an aperturelocated in said reflector, a lamp supporting means mounted adjacent saidaperture for supporting a lamp in said reflector, an elongated invertedopen-sided U-shaped housing located adjacent to and extending outwardlyfrom the apertured portion of said reflector, support means on saidhousing opposite said reflector, an at least partially transparentenclosure located on an integrally formed base portion of said elongatedhousing intermediate said reflector and said supporting means, acentrally located opening in said enclosure communicating with saidhousing, electrical components mounted in said housing and enclosure, adetachable cover located on said open side of said inverted U-shapedhousing, said cover when in its closed operative position completelyenclosing said electrical components located within said housing.

4. A luminaire comprising, an inverted cup-shaped reflector, an aperturelocated in one side of said reflector, a lamp supporting means mountedadjacent said aperture for supporting a lamp in said reflector, aninverted elongated U-shaped housing located adjacent to and extendingoutwardly from the apertured portion of said reflector, support means onsaid housing opposite said reflector, a cross brace located adjacent tosaid support means and extendingbetween the sides of saidhous'ing attheir lower portions, a detachable adapter mounted to said cross brace,securing screws mounted in the upper and lower portions of said housing,said adapter and said securing screws cooperating to firmly hold saidhousing to a support, an at least partially transparent enclosurelocated on a portion of said elongated housing intermediate saidreflector and said supporting means, electrical control componentsmounted in said housing and enclosure, said electrical componentslocated in said enclosure being light sensitive and connected to theelectrical components in said housing to automatically energize saidluminaire.

5. A luminaire comprising, an inverted cup-shaped reflector, an aperturelocated in said reflector, a lamp supporting means mounted adjacentsaidaperture for supporting a lamp in said reflectonan elongated housinglocated adjacent to and extending outwardly from the apertured portionof said reflector, support means in said housing opposite saidreflector, an at least partially transparent enclosure integrallymounted and located on a portion of said elongated housing intermediatesaid reflector and said supporting means, a centrally located opening inthe bottom portion of said enclosure, said opening communicating saidenclosure with said housing, bosses having tapped holes locatedintegrally adjacent each side of said U-shaped housing directly beneathsaid enclosure, a transformer having vertical dove-tailed slots.groovedQin the sides of its horizontally displaced laminations,elongated bolts engageable with said bosses, spacers on said screws tosupport said transformer, said bolts extending upwardly through saiddove-tailed slots to position and align said transformer, saidtransformer being closely associated with all electrical components toprovide easier wiring for said luminaire.

6. A luminairecomprising, an inverted cup-shaped reflector, an aperturelocated in said reflector, a lamp supporting means mounted adjacent saidaperture for supporting a lamp in said reflector, an elongated invertedU-shaped housing located adjacent to and extending outwardly from theapertured portion of said reflector, support means on said housingopposite said reflector, a transformer located within said housing andintermediate said reflector and said supporting means, said transformerhaving a coil mounted on a core, flat plate laminations horizontallydisposed for said transformer core, vertical dovetailed slots centrallylocated in said horizontally disposed flat plate laminations adjacentthe sides of said inverted U-shaped housing, elongated detachablesecuring means extending downwardly from the upper inner side portion ofsaid inverted U-shaped housing to engage the bottom surface of saidcore, said securing means extending downwardly in said dove-tailed slotsto detachably secure said transformer to said housing so that it can beeasily detached to expose the interior ofsaid housing.

References Cited in the file of this patent UNITED STATES PATENTS2,232,169 Diller Feb. 18, 1941 2,489,076 Bjontegard Nov. 22, 19492,666,148 Arvintz'et a1 Jan. 12, 19.54 2,709,224 Garnick May 24, 19552,755,392 Garnick July 17, 1956 2,756,349 Frank July 24, 1956 2,849,574Burns et a1. Aug., 26, ,1958

